Medium resolution EUV observations and network structure

Medium resolution observations have been used to find the fractional emitting area α in three transition region lines. It is found that α is given by DIsup(-k)sub(Mg X) where k varies from 0.78 to 0.51 in the temperature range 2 x 105 to 7 x 105K. The average emitting area in O VI deduced by this method is in good agreement with the results from ATM observations. The fractional emitting areas at different values of the Mg X intensity and at different temperatures are combined to find the variation of the areas with height. This variation is in good agreement with Giovanelli's model of the fractional area of cross-section of a magnetic tube of force in the transition region. (Auth.)